Kernel 4.9 has been released, and (brief!) details of changes are here:  http://lkml.iu.edu/hypermail/linux/kernel/1612.1/01831.html

The latest NVIDIA (375.20) driver works OK, and VMware 12.5.2 with the vmnet and vmmon hack/patches, also works OK.     Hack/patch details are at https://rglinuxtech.com/?p=1838

On my Intel I-7 system (Gigabyte motherboard) I did get some odd ACPI messages at boot time, and it seemed that the boot process tried to detect too many CPUs:

[ 0.000000] APIC: NR_CPUS/possible_cpus limit of 4 reached. Processor 4/0x1 ignored.
[ 0.000000] APIC: NR_CPUS/possible_cpus limit of 4 reached. Processor 5/0x3 ignored.
[ 0.000000] APIC: NR_CPUS/possible_cpus limit of 4 reached. Processor 6/0x5 ignored.
[ 0.000000] APIC: NR_CPUS/possible_cpus limit of 4 reached. Processor 7/0x7 ignored.
[ 0.000000] ACPI: LAPIC_NMI (acpi_id[0xff] high edge lint[0x1])
[ 0.000000] IOAPIC[0]: apic_id 2, version 32, address 0xfec00000, GSI 0-23
[ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl)
[ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level)
[ 0.000000] ACPI: IRQ0 used by override.
[ 0.000000] ACPI: IRQ9 used by override.
[ 0.000000] Using ACPI (MADT) for SMP configuration information
[ 0.000000] ACPI: HPET id: 0x8086a701 base: 0xfed00000
[ 0.000000] smpboot: 8 Processors exceeds NR_CPUS limit of 4
[ 0.000000] smpboot: Allowing 4 CPUs, 0 hotplug CPUs

Other (Intel Core Duo/Quad) systems were OK, so this may be a hardware-specific quirk?    The system booted with the correct (4) CPUs, and everything seems to be working OK, so far..     I will be checking the specific kernel config, to see if there is anything that should be changed..

Robert Gadsdon.  December 11, 2016.